Manned orbiting space stations (and spacecraft generally) have very limited internal volume for the crew. Over a period of time waste material and unwanted objects such as food packaging, failed equipment, experimental by-products, human waste, used filters and so forth are generated and use up available space. It is a desirable advantage to be able to dispose of such waste material during a mission so as not to proliferate or increase space debris by ejecting it into space or requiring it to be stored in the spacecraft.
The reason that waste material cannot simply be ejected into space is that such ejected waste material occupies a volume and a trajectory for a time period and can be a hazard to existing and future space missions because of "hard body" impacts where one solid high velocity body mass impacts with another solid high velocity body mass which produces smaller and more numerous high velocity debris elements from the larger debris body masses. The obvious proliferation of debris in this manner reduces "free" space and increases the hazards of future space operations which will encounter such debris. Space debris has a relatively long life and thus presents a problem of removal from space.
Orbital lifetime for a space object if not restricted can range into hundreds of years. The lifetime is a function of energy. As an orbiting object loses energy principally through friction, in time it will descend to progressively lower orbits and eventually fall to earth. PRIOR PATENT ART
U.S. Pat. No. 3,421,714 (Class 244/1) issued to W. G. Koerner on Jan. 14, 1969 relates to a passive vehicle for conveying small payload packages or capsules from a space vehicle to the earth. The vehicle is comprised of a storage tank 10, radial fins 11 and a bead 12 on the outer edges of the fins 11. The bead 12 or the fins are arranged to rotate the tank 10 about its longitudinal axis during re-entry to alleviate heating problems and discourage a tumbling action. The fins are also intended to cushion the tank upon ground impact.
U.S. Pat. No. 4,518,137 (Cl 244/133) issued to D. G. Andrews on May 21, 1985 teaches that recovery of a space vehicle is enhanced by use of a braking or drag member. As a spacecraft is guided towards re-entry and approaches the earth atmosphere it is oriented to have the nozzle of the main rocket motor leading. The braking member is deployed and the rocket motor is operated to provide a cooling layer of gases and change the velocity of the space vehicle. When the vehicle is slowed down to a proper velocity, the braking member is jettisoned.
U.S. Pat. No. 4,549,464 (Class 89/1809) issued to D. K. Hawkinson Oct. 29, 1985 relates to an inflatable shroud which is compacted within an available cylinder or silo volume and inflated by a gas generator to an aerodynamic shape.
U.S. Pat. No. 4,832,288 issued to R. T. Kendall et. al. on May 23, 1989 relates to a recovery system which has an inflatable torus system which can be deployed to decelerate a vehicle reentry into the atmosphere. Explosive squib bolts or the like are operated to open the closure for the torus device.
Other patents showing drag devices include the following:
U.S. Pat. No. 4,958,565 issued to M. A. Koch on Sep. 14, 1990, relates to a decelerator for stabilizing the drop of a bomb from an aircraft. The problem set forth in the patent is the wide disparity between the aircraft ejection speed and the descent speed which can damage the bomb or the parachute. The disclosure describes a triangular shape which has scoops to inflate the interior chamber between front and rear panels of the decelerator.
U.S. Pat. No. 4,005,655 issued to N. Kleinschmidt on Feb. 1, 1977 relates to an aerodynamic stabilizer and retarder apparatus for use with free fall weapons. The problem is bomb delivery from high speed low level aircraft. A fabric bag is inflated by ram air after the bomb is launched and air scoops provide a drag. The drag can be varied by the use of other drag members.
U.S. Pat. No. 4,565,341 issued at A. T. Zacharin on Jan. 21, 1986 discloses a collapsible decelerator for an aerial bomb which has a star shaped hollow member.
U.S. Pat. No. 3,514,058 issued to G. J. Sloan on May 26, 1970 relates to a combination self inflating retardation and flotation device for recovery of instrumentation packages descending from a high attitude. The device includes a pear shaped bag construction with shroud lines 34 which converge to a riser line 38. In operation atmospheric air inflates the bladder 14 and a skirt member 22 is inflated and upon engagement with water limits the depth of submergence.